Test modes for modern set-top boxes (STBs) may be protected by a plurality of secure authentication mechanisms. Authentication mechanisms in a STB may be required to authenticate a single user or multiple users. In STB applications such as accessing system buses and interfaces, a user may need to provide specific information to enable the system to confirm its identity. The information may be in the form of passwords or responses by the user to the STB challenges.
One of the common approaches to authenticating a user identity is the use of passwords. For example, the user may provide a password, and the STB may validate the password. If the password is associated with the user, that user's identity may be authenticated. If the password is not associated with the user, the password may be rejected and the authentication may fail.
A common hidden unreadable value may be stored in a chip to generate the password. A secure passing algorithm, for example, an algorithm modified from advanced encryption standard (AES) may be adapted to protect the password from an attacker trying to guess it. The password scheme may be used for preventing unauthorized users to access security sensitive areas of a device, for example, observing and controlling test access ports (TAPs) on a software controlled basis. One of the problems associated with passwords are that they are reusable. If an attacker breaks a password, he may later reuse the password to gain access to other STBs. A set-top box (STB) may not be able to distinguish between an attacker and a legitimate user.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.